Miss Duff’s been sticking to her strict Pilates routine to help keep off the post-baby pounds and it’s definitely working.

The former Disney Channel starlet is looking better than ever and she recently explained, “Seriously, my body changed in three weeks. I’ve always been really muscular; that’s why pilates is good for me. I have broad shoulders and if I do weights or something I’ll bulk up and feel manly, but pilates (sic) lengthens me out. Also you feel really powerful.”